有没有办法简化这个嵌套的 if-else 语句？

Question

我有这个伪代码，它都播放不同的音频文件。 我读到嵌套 if 的时间复杂度为 O(m+n)，我认为这还可以，但如果有一种方法可以简化它或降低时间复杂度，那就太好了。

btn_G.onTouchListener(){
  Case Motion.Action_Down:
    if(high_octave){ 

      if(move){ //if the phone is moving
      
        if(sharp){ //if it's a sharp note
        
          if(vibrato){ //if it's vibrato
            Gstream = G.play(loop) //loop a vibrato, sharp, high octave G note

          } else { //if there is no vibrato
            Gstream = G.play(loop) //loop a normal, sharp, high octave G note
          }
          
        } else { //if all are normal notes, no sharps
        
          if(vibrato){ //if there is vibrato
            Gstream = G.play(loop) //loop a vibrato, normal, high octave G note

          } else { //if there is no vibrato
            Gstream = G.play(loop) //loop a normal, high octave G note
          }
          
        }
      } else { //if the phone is not moving
      //if the phone doesn't move, doesn't matter if there is vibrato or not
      
        if(sharp){ //if it's a sharp note
          Gstream = G.play(once) //play a sharp, high octave G note only once

        } else { //if all are normal notes, no sharps
          Gstream = G.play(once) //play a normal, high octave G note only once
        }
        
      }
    } else if(mid_oct){ #middle octave
        //repeat all of that but with middle octave G note

    } else { #low octave
        //repeat all of that but with low octave G note
    }
  Case Motion.Action_Up:
    Gstream = G.stop() // stop the audio
}

那只是一个按钮。 我有 8 个按钮需要这样做。 我想过使用哈希列表，但为了创建列表，我也会检查这样的条件，所以它会是一样的，不是吗？

我也发现了这个，但我不是像嵌套 if 那样分离条件吗？ 因为我有 8 个按钮，所以它也会很长且重复？

即使有所有条件，有没有办法缩短它？

抱歉，我对此有点陌生。

Answer 1

您可以为条件使用位掩码，并将它们分组以用于switch语句：

int cond1 = 0x1;
int cond2 = 0x2;

switch(cond) {
  case cond1|cond2:
    // both  are true
    break;
  case cond1|0x0:
    // only cond1 true
    break;
  case 0x0|cond2:
    // only cond2 true
    break;
  case 0x0|0x0:
    // both are false
    break;
}

Answer 2

我最终将它们分成不同的方法，如下所示：

G_btn.onTouch{
  Case Motion Down:
    if(up){
      horizontal_method(G5, G#5, gStream)
    } else if (down) {
      horizontal_method(G4, G#4, gStream)
    }
  Case Motion Up:
    stop_audio_method(gStream)
}

public void horizontal_method(note, sharp, stream){
  if(horizontal){ //if phone is moving
    loop_num = -1 //looping
  } else { //phone not moving
    loop_num = 0 //play once
  }
  rotate_method(note, sharp, stream, loop_num)
}

public void rotate_method(note, sharp, stream, loop_num){
  if(rotate){ //if sharp
    stream = soundpool.play (sharp, loop_num) //can be looping or not, depends on the loop_num
  } else { //not sharp
    stream = soundpool.play (note, loop_num)
  }
}

public void stop_audio_method(stream){
  stream = soundpool.stop() //stops that specific stream
}